This invention relates to a computer system, and more particularly to a method for backup and recovery of the long filename under the computer system (e.g. DOS operation system) that does not support the long filename designation.
In Microsoft Win95 and sequential Windows operation system, one of the useful improvements is enabling the possibilities for designation of long filename. It releases users from the restrict of eight characters filename. However, the prior operation system (e.g. Win 31 and DOS) does not support the long filename designation. In order to be compatible with DOS, the Win95 system creates a short filename to access the corresponding file under the non-supporting system. But the DOS 7.0 of Win95 still cannot create the long filename if Win95 does not start. It is necessary to create the long filename in many conditions such as in the condition of the backup and recovery of operation system under the DOS.
In the real world of computer operation the crash of the operation system happens. Once the user who did not back up the operation system has to reinstall it when it is crashed. Nevertheless, reinstalling the operation system is a complicate problem, so it is necessary to back up the operation system previously to avoid the inconvenience.
It is an object of this invention to provide a method for backup and recovery of the long filename under the computer system that does not support the long filename designation.
It is another object of this invention to provide a method for backup and recovery of the long filename in the computer system free from language restriction.
It is still another object of this invention to provide a method for backup and recovery of the long filename under the circumstance that the computer system can not start.
The technique of this invention is to read the file directory table (FDT) from the logic partition of the hard disk by calling the basic input output system (BIOS) function, then transfer the long filename and short filename items into long filename format and write to a backup file. The backup file will be reversed under the environment that does not support the long filename. First, search the short filename of each directory and sub directory and obtain the data in the back up file. After that, write the matched long filename back to the original FDT to avoid the limitation of DOS that does not support the long filename designation.
In accordance with the above-mentioned objects, this invention discloses the method that can back up and recover the long filename when Windows system is not able to start. That is, it can work under any language system that the operation system belongs. For example, it can back up and recover the long filename of Win95 traditional Chinese version in Win95 simplified Chinese version.